Prevention and Treatment of Guppy Diseases

Friends who keep guppies have always had a great confusion, that is, their beloved fish always frequently develop lesions. Usually, few sick guppies can be treated and fully recover; even if cured, their ornamental value is greatly reduced. Therefore, we must do a good job of prevention in this regard. Common guppy diseases include: 1) pin tail, 2) white spot disease“also known as ichthyophthiriasis”, 3) fin and tail rot, 4) saprolegniasis“also called white cotton disease”, 5) bacterial enteritis, 6) white head and white mouth disease, 7) dropsy, 8) skin congestion and ulceration. So let us take a look at these diseases.

1) Pin tail

There are many good posts on forums about treating pin tail, so I will not say more here. I will only introduce some of my personal experience in preventing pin tail in fry. My method is to put the breeder fish that have given birth into a small tank “using water from the original tank” and float it in the original tank where the breeder fish are kept. After the fish finish giving birth, remove the adult fish and put them back into the original tank. The fry live here for about a week, with the bottom siphoned twice a day, and after siphoning, top up the water. Be sure to use water from the original tank to top up “whichever tank the small tank is floating in, use water from that tank”. However, the water for keeping breeder fish must not be too old; it must be clean, transparent, and free of disease. In this way, the temperature will remain consistent, the water quality will also be consistent, and the water quality is also water that has already been used to keep fish, so it is very mild to the fry. After topping up the water for the fry every day, do not forget to also top up the water level of the original tank with aged new water. When the fry have grown here for a certain time, you can consider giving them a larger space environment “tank transfer”. At this time, the fry also have a certain ability to resist the external environment. First prepare a tank suitable for them, then siphon out half of the original tank water “the water used for keeping breeder fish” and pour it in, then slowly pour the fry from the small tank into it together with their water. After that, use the drip method to introduce new water of the same temperature until the water level line is reached. This basically completes the process, and the effect is excellent. Everyone can give it a try.

2) White spot disease“also known as ichthyophthiriasis”

The whole body of the fish is covered with small white spots less than 1mm in diameter. When the condition is severe, the body surface seems to be covered with a white film, scales fall off, and fin rays split and rot. When gill tissue is heavily parasitized, mucus increases, gill lamellae are destroyed, respiration is affected, and the fish swims slowly at the water surface and soon dies. This disease generally breaks out easily in tanks with turbid water and low temperature. Because Ichthyophthirius multifiliis has the physiological characteristic of not tolerating high temperatures, the simplest treatment is to raise the temperature to 28 degrees, and the Ichthyophthirius multifiliis can then fall off and die. There is also a type of white spot disease caused by high temperatures, and this type can only be treated with medication. I usually use methylene blue or mercurous nitrate for treatment. Generally, the water is dosed until it is light blue. Remember that copper sulfate must never be used for white spot disease, otherwise the fish disease will become more severe.

3) Fin and tail rot

That is, the dorsal, tail, and other fins of the sick fish split and rot. Generally, yellow powder has a good effect “use 2 grams of pure powder per 100 liters of water”. There are also some cases caused by water quality, such as burned tail caused by new water; this type will recover on its own without adding any medication. Burned tail caused by acidic water will also naturally improve after changing the water.

4) Saprolegniasis“also called white cotton disease”

It is a disease caused by fungi. Saprolegnia is an opportunistic pathogen and is mostly saprophytic. Therefore, injury to the fish body is the trigger for the disease. When the mold invades from a wound on the fish body, no abnormality can be seen with the naked eye. When it can be seen with the naked eye, the hyphae have already penetrated deep into the muscles, spread and expanded, and grown outward into cottony hyphae, resembling grayish-white cotton wool. Generally, fish without body surface injuries are not easily infected. Water temperature that is too low is also one cause of this disease. Malachite green is the best medication for treating this disease, but I do not support using this medication because its toxicity is too great and difficult to control, and improper use can lead to a tragic outcome. I suggest raising the temperature, adding salt, and adding yellow powder when the disease is mild, and using formaldehyde solution “analytical grade” at 5 milliliters per 100 liters of water when it is severe.

5) Bacterial enteritis

The pathogen is enteric Aeromonas punctata. It is mainly caused by overfeeding; the fish's greediness for food is one of the triggering factors, and in addition, poor aquaculture environmental factors and high organic matter content in the water also cause it. In the early stage of the disease, the fish's appetite decreases, body color becomes dark and lacks luster, and there are no obvious external symptoms. In the later stage, the sick fish shows abdominal swelling, loose scales, red and swollen anus, and when the abdomen is cut open, yellow abdominal fluid flows out with a foul odor. For early-stage enteritis, using the old three methods for three consecutive days has a very good effect (feeding must be stopped). In the middle stage, furazolidone plus salt has a certain effect. In the late stage, flush it down the toilet.

6) White head and white mouth disease

The pathogen is Aeromonas hydrophila. The skin pigment from the tip of the snout to the eyeball of the sick fish fades and becomes milky white, the lips appear swollen, and opening and closing malfunction, thus causing difficulty breathing. The skin around the mouth ulcerates, with flocculent matter adhering to it, and the fish soon dies. This disease is highly contagious. Once discovered, treat it as soon as possible. According to my experience, in the early stage, yellow powder plus salt plus furazolidone has a certain effect. The specific drug is formaldehyde solution at 5-8 milliliters per 100 liters of water, used continuously for 3 days. Remember that two-thirds of the water must be changed every day before topping up and adding medication, and increase the oxygen supply. Recently I heard that chlorine dioxide also has a good effect, but I have not used it myself. Friends who are interested can try it themselves.

7) Dropsy

The pathogen is Pseudomonas punctata. The scales on the front part of the body or abdomen of the sick fish open outward, the base of the scales becomes edematous, forming pinecone-like scales, and when lightly pressed by hand, fluid seeps out, and the scales also fall off accordingly. In severe cases, the body surface becomes congested, the eyeballs protrude, the abdomen swells, breathing becomes difficult, the body loses balance, and the fish soon dies. However, this disease is not contagious. There are many causes of this disease. The commonly seen ones are caused by new fish not adapting to the water quality when they first arrive, unstable water quality, and unreasonable feeding after metabolic disorder. I suggest giving up treatment. There are no good therapeutic drugs or methods for this disease. Even if cured, it loses its ornamental effect. I once had a goldfish that gradually improved after half a month of treatment with erythromycin plus allicin (this was the only time it was cured), but new flesh grew under the scales and never went away. It was really too ugly.

8) Skin congestion and ulceration

This disease is generally caused by cross-infection, with a mortality rate as high as over 60%. Generally, it is caused by operational errors, such as failure to do a good job of quarantine for newly introduced fish, pouring tank A into tank B, and so on. What is cross-infection? It is a behavior in which fish A transmits the bacteria it carries to fish B, and at the same time fish B also transmits the bacteria it carries to fish A. Even if the purchased fish are healthy, they must be quarantined before being combined into a tank, because even healthy fish themselves carry more or less bacteria. The bacteria they carry have already given them antibodies and will not cause disease in themselves, but they will transmit them to other fish, and the other fish will then develop disease. By the same principle, other fish will also transmit bacteria back and cause it to develop disease as well, forming this mutually infecting symptom. Treatment is relatively difficult. It is recommended to use 1 formaldehyde + yellow powder + oxytetracycline. 2 Lecai's Jiefushuang + companion. 3 Taiwan, China Huihong's medication for preventing cross-infection.