1. What is CL?
Cervical Lymphadenitis is a swelling or abscess of the cervical lymph nodes in a guinea pig’s neck.
2. What causes CL?
According to recent literature, Streptococcus zooepidemicus, a gram-positive Lancefield Group C streptococcus, is the most common cause of CL. Although not as common, bacteria such as other Streptococcus spp., Streptobacillus moniliformis, Fusiformis and Pasturella spp. may cause CL.
It is also important to note that other diseases, such as Cavian leukemia, and bacteria, such as Yersinia pseudotuberculosis, Bordetella and Salmonellae (S. linate) may cause CL-like symptoms.
A bacterial culture of the swelling/abscess must be taken to find out the definitive cause of the CL.
3. Mode of CL transmission
Almost all the sources agreed that abrasions to the oral mucosa and conjunctiva were common modes of transmission. The CL-causing bacteria was also thought to be transmitted through skin and/or bite wounds. A few of the more recent sources stated that transmission could even be through aerosol or inhalation of the bacteria.
4. What is CL’s incubation period?
No information was found for a definitive CL incubation period in guinea pigs. However, Group C Streptococcus incubation periods in other animal species ranged from 1 day to 2 weeks.
5. What are available treatment methods for CL?
Many sources written from a medical or laboratory viewpoint recommend euthanizing affected guinea pigs. However, many pet owners would prefer to treat a beloved pet first before carrying out this option. Treatment for the pet owner’s guinea pig would consist of the following:
- Isolate the infected guinea pig BEFORE the lymph node abscesses rupture to prevent spread of the disease-causing organism.
- Treat with surgical drainage of lymph nodes.
- Lavage/flush abscesses.
- Antibiotic therapy for 7-14 days.
Systemic antibiotics such as enrofloxacin (Baytril) or chloramphenical are effective in treating CL. However, Baytril is usually considered the antibiotic of choice to treat adult guinea pigs.
Young guinea pigs generally should not be treated with Baytril as it is believed to affect their growth. You may wish to discuss Baytril and the risks of using it on a young guinea pig with your vet if your pet has CL. Note that Bactrim and Doxycycline are safe antibiotic alternatives for young pigs but a veterinarian must be consulted to see if they would be effective against CL.
Click here for more Baytril and Chloramphenicol dosing information:
- Baytril -- (Enrofloxacin [oral, subcutaneous or intramuscular])
Oral Dose: 2.5-10.0 mg/kg q12h
- Chloramphenicol --(Chloramphenicol sodium succinate [Subcutaneous, Intramuscular], Chloramphenicol palmitate [oral])
Oral Dose: 50 mg/kg q12h
- Cephaloridine -- 25mg/kg, intramuscular dose for 14 days.
Cephalexin -- 50-100mg/kg, intramuscular dose for 14 days.
7. What is the recovery time for CL in guinea pigs?
No specific recovery time for guinea pigs was found. However, in horses with Streptococcus equii, another Group C Streptococcus which causes "Strangles" (similar to CL in guinea pigs), the total time for the disease to run its course is approximately 3 weeks.
In other animal species, Streptococcal spp. have been isolated for as long as 4 weeks after symptoms of disease have gone. However, it is unknown whether guinea pigs would continue to shed Streptococcus zooepidemicus for a similar length of time after their abscesses have drained and healed.
8. Are recovered guinea pigs carriers of CL?
There has been some indication that there could be carrier animals.
9. Is CL transmissible to humans?
Several sources stated that Group C Streptococcus, including Streptococcus zooepidemicus, may (but rarely) cause disease in humans. The people most likely to be affected would be the elderly or those with weakened immune systems.
10. Is there a vaccine available against CL in guinea pigs?
Yes and no. According to one source, the killed bacterins which would be found in a vaccine are not effective in preventing CL. However, studies have found that scratch injection of the oral mucosa with Streptococcus zooepidemicus (recovered from swine) stimulates immunity in the guinea pig.
- *Limiting the amount of coarse feed, especially very coarse stalky hay, may aid in decreasing the incidence of CL because irritation to the oral mucosa would be less. Hay is an important part of a guinea pig's diet, though. Therefore, a high-quality, dust-free, mold-free grass hay should be available to your guinea pig at all times.
- *Chronic CL infections can be exacerbated by stress. Lack of Vitamin C may also play a role in CL infections.
- *A few sources said that Group C Streptococcus is relatively fragile in the environment. The environment should be properly disinfected. See Table 2 for common disinfectants and their germicidal activity.